CBS News has a strange way of marking Valentine's Day. On the Sunday after Wednesday's romantic dinners and flowers, "Sunday Morning" linked the day to a deep study of marital infidelity.

Reporter Tony Dokoupil found an expert: therapist Esther Perel, author of "The State of Affairs: Rethinking Infidelity." He also found two cheating wives who explained their cheating ways without any guilt. CBS insisted we need to "rethink our attitude" toward the sin of adultery.

It happens in every period of time and every culture, CBS explained. So does murder, and it's uncertain whether CBS thinks we must "rethink" that, too. There should be no villains when infidelity happens, Perel lectured: "To think about them just as a good person and a bad person does not help the millions of people who are experiencing it -- the children, the friends, the family."

Perel found fault not with cheaters but with those who label them as such. "We do not claim moral superiority just because we haven't cheated," she insisted. "And just because we haven't had sex with somebody else, we think we are the mature, and the committed, and the superior? This has got to change, or we will never have an honest conversation about this."

An "honest conversation" is code for rewriting morality. Except morality can't be rewritten. It just is. Morality can't be altered, but it can be ignored, and that's what the "experts" want to accomplish.

Dokoupil announced a new equality of the sexes: "According to a survey by the Kinsey Institute at Indiana University, female philanderers are catching up with their male counterparts for the first time on record." What is that? An achievement?

CBS spotlighted "Kristie" and "Daphne," who wouldn't use their real names. They had one thing in common regarding their cheating. Each had used the "married dating" site Ashley Madison. It sounded like a tawdry commercial as CBS relayed, "The site is booming, with 20,000 new members a day."

Kristie went shopping for dates after her husband said something "very disrespectful, very hurtful" to her. "I pulled my phone out, and I went to my phone and I said, 'woman looking for men to have affairs with,'" she said. When her husband found text messages from her lover, Kristie says, she just ended it: "I didn't deny it. I'm like, 'Yup, and I want a divorce.'" There was no remorse, just relief.

Daphne, who also hid behind a screen, said she had a good marriage for 22 years, but her husband has Alzheimer's disease, and morality got in the way. "I wasn't going to be able to continue taking care of my husband if I didn't have some fun," she claimed. "(B)ecause I was impatient with him. I cried. I was just angry. And now I'm much more patient with him. I don't get angry. I'm a better wife now than I was."

She's a better wife ... now that she cheats. And he has Alzheimer's, so it's a win-win?

The CBS story ended on a high note, as the cheater Kristie announced that she married the boyfriend she found on Ashley Madison. She was asked how saying those vows felt. She said, "I know ... it's forever!" Or until she gets the hots for the next guy.